A configuration of a conventional drum type washing and drying machine will be described hereinafter with reference to FIG. 4.
As shown in FIG. 4, main body 1 of the drum type washing and drying machine has therein water tub 3 supported by a suspension structure (not shown) and damper 2, and opening 4 of water tub 3 is opened and closed by a door (not shown). Further, rotary drum 5 provided with multiple drum perforations 7 and baffles 8 is rotably installed in water tub 3 and is driven by motor 6. Wash water supply valve 9 for supplying water into water tub 3 and cooling water supply valve 10 for supplying cooling water are installed in main body 1. Further, water outlet 11 is formed at water tub 3 and is connected to water drain conduit 13 via water drain pump 12.
An air circulation channel for a drying process for laundry in rotary drum 5 includes blower 14 for blowing air into water tub 3 through air injection port 15, heater 16 connected thereto, heat exchanger 17 disposed between water tub 3 and blower 14, and cooling water hose 18 directly connected to cooling water supply valve 10 and communicating with heat exchanger 17 (see, for example, Japanese Patent Laid-Open Application No. H11-333185).
Operation of the washing machine with the above configuration will now be described. When a washing process is initiated after loading laundry into rotary drum 5, wash water supply valve 9 is opened, so that fresh water is supplied in water tub 3 up to a predetermined water level. Thereafter, rotary drum 5 is driven to rotate at a rotation number of about 50 rpm. As a result of the rotation of rotary drum 5, the laundry in rotary drum 5 tumble and is lifted up by baffles 8 and then plunged into the water over and over. As the washing machine repeats this agitation process to loosen dirt, the laundry is cleaned by wash water with detergent dissolved therein and the repeated beating motions on the water surface. At the conclusion of the wash cycle, water drain pump 12 is driven, so that soiled wash water is drained via water drain conduit 13. After the soiled wash water is pumped out, a water-extracting process is performed by way of spinning rotary drum 5 with a rotation number of about 1000 rpm. After the water-extracting process, a drying process is started.
During the dry cycle, while the laundry accommodated in rotary drum 5 is agitated as a result of the rotation of rotary drum 5 as in the washing process, hot air heated by heater 16 is blown to the laundry in rotary drum 5 through air injection port 15 by blower 14. As a result, the residual moisture in the laundry in rotary drum 5 is evaporated by the hot air. Then, the hot and humid air with the moisture from the laundry is directed to heat exchanger 17 to be cooled down by cooling water supplied in heat exchanger 17. As a result, the hot and humid air is cooled and dehumidified because its moisture is condensed out. Then, the dehumidified air is heated again by heater 16 and is re-circulated into rotary drum 5 to further dry the laundry. By having this dry cycle, the washing and drying machine can dry the laundry in rotary drum 5.
In the conventional configuration of the washing machine, however, since heat exchanger 17 has an approximately hollow rectangular shape, heat exchanger 17 needs to be designed sufficiently large to ensure a satisfactory drying. However, the limited space in main body 1 is inadequate to accommodate the heat exchanger size requirement.